In recent years, flat panel display devices that use flat panel display elements such as liquid crystal panels and plasma display panels are increasingly used as display elements for image display devices, such as television receivers, instead of conventional cathode-ray tube displays, allowing image display devices to be made thinner. Liquid crystal panels used in liquid crystal display devices do not emit light on their own, and therefore, it is necessary to provide a separate backlight device as an illumination device.
One of the known backlight devices is a direct illumination type backlight device in which light is directly supplied to the liquid crystal panel from the rear surface thereof. In such a direct illumination type backlight device, a light source substrate having light sources such as LEDs disposed thereon is provided along a bottom plate of a chassis that is used as a case. On the light source substrate, a wiring pattern for electrically connecting the respective light sources to each other is formed, and terminals provided at both ends of the wiring pattern are electrically connected to a connector that is provided at one end of a power supply wiring line extending from a power supply substrate. In this way, power is supplied to the respective light sources from the power supply substrate through the connector. Patent Document 1, for example, discloses a conventional example of such a direct illumination type backlight device.